1. Field of the Invention
This invention relates to the application of liquids, and more particularly to an apparatus for applying various liquids to various items at a controllable flow rate.
2. Description of the Prior Art
Many devices have been devised for applying liquids to various items such as a vinegar-water solution to windows, wax on floors, herbicides on weeds, and the like. These prior art devices range all the way from relatively inexpensive, simple mechanisms such as a sponge mounted on the end of a stick for window washing and floor waxing purposes, to much more expensive and complex mechanisms such as spray equipment for applying herbicide. No single device is suited for all liquid application tasks in that each has its limitations and drawbacks.
For example, the simple stick-mounted sponge is normally used by dipping the sponge into the window washing liquid and wipingly applying the saturated sponge to the glass. Such a method almost invariably results in drops landing on the floor as a result of transporting the applicator device from the liquid supply to the glass. Further, the saturated sponge will apply an over abundance of the liquid at the start of the wiping operation and will dry out near the end. The above really presents no serious problems other than requiring that the liquid be spread by repeatedly passing the sponge over the glass to produce a substantially even coating and that the area be cleaned up after completion of the task. Such a device, however, cannot be properly employed for applying herbicide on weeds in that the drops may kill vegetation other than the weeds and will be inconsistent to a point where excessive amounts of this costly herbicide will be applied to some of the weeds and insufficient amounts will be applied to others.
Even the expensive and relatively complex spray applicator devices are not suited for all liquid application tasks. For example, spray application of window washing liquid or floor wax could result in damaged or ruined curtains, rugs, furniture and the like. Further, spraying equipment is not even well suited for all types of herbicide application tasks. To illustrate this point, consider that herbicides, either of the systemic or conventional types, may be applied by a conventional spray method when complete destruction of all plant life in a sprayed area is desired. However, selected herbicidal tasks such as weeding operations, require that the herbicides be selectively applied only to the vegetation that is to be destroyed, and this, of course, eliminates the usage of spraying application techniques.
For the above reasons, it will be seen that due to the multiplicity of liquid application tasks, many specialized devices have been developed with each device being designed to handle a particular type of job.
To be more specific, a special herbicide applicator which is designed primarily for use with systemic herbicide has been developed for use in cultivated fields and this device is in the form of a trailing wick that is attached to a tractor, or other farming mechanism. The special trailing wick applicator is carried by the farm machine so as to follow the furrows between the crop plants. In this manner, the trailing wick applicator will wipe the herbicide on the weeds that are growing in the furrows only in that the trailing wick cannot be allowed to come into close proximity with the crop plants. Thus, such a device is limited in its use in that it cannot be employed to kill vegetation that is proximate any plants that are not to be destroyed, due to the fact that the trailing wick applicator cannot be controlled with any desired degree of accuracy.
A hand held herbicide applicator has been developed for selective application purposes, and that applicator is fully disclosed in U.S. Pat. No. 4,027,986. Briefly, this particular prior art applicator comprises a reservoir handle with a fill and vent control plug on its upper end and an applicator head on its other end. The applicator head is a bell-shaped enlargement which is filled with a foam rubber material and has its lower end wrapped with a carpeting material. The herbicide flows from the reservoir handle through an orifice and saturates the foam rubber and the carpeting material. Although this applicator can be used for selectively applying herbicide on vegetation, its usage is limited to a more or less dabbing type of application due to the particular head configuration. The applicator head is designed primarily for dabbingly applying the herbicide on newly cut tree trunks to kill the root systems thereof and cannot practically and efficiently be used to wipingly apply herbicide to, for example, weeds which have outgrown slower growing grasses, and the like, and it is awkward to use in between closely spaced crop plants.
To the best of my knowledge, no single liquid applicator device has been developed which can be satisfactorily employed for wipingly applying various liquids on various items.